This invention relates to a passenger seat with a low profile seat back recline locking assembly. Passenger seat frames are constructed from modular set of components designed to be lightweight and conformable to various aircraft cabin conditions. The lower seat chassis is constructed of leg modules. The upper seat chassis is constructed of section assembly modules. The leg modules and section assembly modules are assembled by attachment to lateral tubular beam elements to form a ladder frame assembly. A seat bottom and a seat back are mounted to the ladder frame assembly to form the passenger seat. The seat back typically includes a recline unit which allows the seat back to be moved between relatively upright and reclined positions for passenger comfort and ingress/egress requirements. The location of the section assembly modules is controlled by the aircraft fuselage lines and statutory aisle requirements. The section modules carry pivots for both sides of the seat back and an additional pivot on one side to carry the reaction loads of the recline unit of the seat back.
In current coach class seat designs, the overall length of the hydraulic cylinder recline unit is approximately 8 inches between attachment points. The actuator of the recline unit is in line with the axis of the cylinder. These units have a stroke of between xc2xd inch and xc2xe inch. The physical size of the cylinder influences where in the seat the cylinder is located.
Recline units currently used in coach class seat designs are usually positioned horizontally beneath the seat bottom to either the left or the right of the passenger placement location. The current location results in a thicker seat bottom cushion that would otherwise be needed to prevent passenger discomfort associated with sitting on the unit. Additionally, portions of the bottom cushion at each side must be removed to allow room for the recline unit, thereby increasing manufacturing costs of the bottom cushion and reducing the volume of buoyant foam required to meet to meet FAA regulations for floatation bottom cushions. The thick bottom cushion also raises the overall height of the bottom cushion. This compromises comfort for passengers of shorter physical stature.
The recline unit according to the present invention is less than 5 inches between attachment points, and has a xc2xd inch stoke. The actuator of the recline unit is located beside the cylinder, thus contributing significantly to the overall reduced length. This shorter length allows the unit to be located in a nearly vertical position to one side of the passenger placement location and behind the passenger. The seat pan therefore has a clean appearance without local protuberances. As a result, the bottom cushion can be thinner, less complex, more comfortable and lighter than those in current use. Recline of the seat back is unaffected, and is completely transparent to the passenger.
Therefore, it is an object of the invention to provide a passenger seat with a low profile seat back recline locking assembly.
It is another object of the invention to provide a passenger seat which utilizes a hydraulic cylinder which is shorter than conventional seat recline cylinders.
It is another object of the invention to provide a passenger seat wherein the unit is located in a nearly vertical position to one side of the passenger placement location and behind the passenger.
It is another object of the invention to provide a passenger seat including a seat pan having a clean appearance without local protuberances.
It is another object of the invention to provide a passenger seat that permits the bottom cushion to be thinner, less complex, more comfortable and lighter than those in current use.
These and other objects of the present invention are achieved in the preferred embodiments disclosed below by providing a passenger seat with low profile seat back recline locking assembly, comprising a seat bottom chassis including a plurality of leg modules and section assembly modules, a plurality of beam elements carrying the leg modules and section assembly modules in spaced-apart relation to each other to define a ladder frame assembly and a seat back unit pivotally-mounted between two of the section assembly modules for permitting the angle of the seat back relative to the seat bottom chassis to be varied as desired by the passenger. A recline unit is provided for controlling movement of the seat back and locking the seat back in a desired recline position, and comprises a fluid cylinder assembly pivotally-mounted by a first end thereof to a section assembly module of the seat and by an opposite second end thereof to the seat back unit. The cylinder assembly has a longitudinally-extending axis extending in alignment with the longitudinally-extending, generally vertical plane of the seat back. An actuator is positioned astride and operatively connected to the fluid cylinder adjacent one or the other of the first and second ends thereof. An occupant-activated seat back recline control allows the occupant to maintain the seat back in a normally-locked condition relative to the seat bottom chassis and for permitting the occupant to release the normally-locked condition of the cylinder assembly by activating the seat back recline control to thus permit movement of the seat back to a desired position and deactivating the seat back recline control to lock the seat back in the desired position.
According to one preferred embodiment of the invention, the fluid cylinder assembly is pivotally-mounted to the section assembly module of the seat by a stepped pivot shaft having a first axially-extending segment having a pivot axis which is radially-offset from a second axially-extending segment for providing translational movement to the fluid cylinder assembly simultaneously with the pivotal movement of the fluid cylinder assembly for increasing the effective stroke of the fluid cylinder assembly.
According to another preferred embodiment of the invention, the fluid cylinder assembly is pivotally-mounted by the first and second ends thereof to the section assembly module by respective first and second pivot tubes on which the fluid cylinder assembly is mounted and by the first and second pivot tubes being positioned in respective first and second pivot holes formed in the section assembly module.
According to yet another preferred embodiment of the invention, first and second locking spacer collars are positioned in surrounding position on respective first and second pivot tubes intermediate the section assembly module and the seat back unit pivoted thereto.
According to yet another preferred embodiment of the invention, each of the first and second collars include an attachment device for locking the respective first or second collar to the section assembly module against both axial and radial movement relative thereto.
According to yet another preferred embodiment of the invention, the attachment devices each comprise an elongate member positioned through an attachment hole in the collar and a mating attachment hole formed in the section assembly module.
According to yet another preferred embodiment of the invention, each the collar is pear-shaped and the attachment hole therein is radially offset from the pivot hole therein.
According to yet another preferred embodiment of the invention, the section assembly module includes a stepped surface underlying the attachment hole in each of the first and second collars whereby when the portion of each of the collars surrounding the respective pivot hole is in contact with the section assembly module, the portion of the collar surrounding the pivot hole is spaced-apart from the attachment hole in the section assembly module, and by tightening the attachment member each of the collars is deflected inwardly towards the respective attachment screw hole in the section assembly module and locked against the respective pivot tubes.